Fluoromatch Im An Interactive Software For Pfas Analysis By Ion Mobility Spectrometry
FluoroMatch IM - An Interactive Software for PFAS Analysis by Ion Mobility Spectrometry
Terms
- HRMS: High-resolution mass spectrometry.
- IMS (Ion Mobility Spectrometry): Separates ions based on charge, size, and shape before mass analysis.
- LC-IM-HRMS: Liquid chromatography coupled with ion mobility and high-resolution mass spectrometry.
- CCS (Collision Cross Section): A reproducible physical measurement describing an ion's effective size and shape in the gas phase.
- DTIMS: Drift Tube Ion Mobility Spectrometry.
- TWIMS: Traveling Wave Ion Mobility Spectrometry.
- cIMS: Cyclic Ion Mobility Spectrometry.
- Mobilogram: Plot of ion intensity versus drift time.
- Drift time: Time required for an ion to traverse the ion mobility cell.
- Orthogonal evidence: Independent evidence supporting an identification (e.g. CCS in addition to m/z).
- Feature: A detected ion characterized by m/z, retention time, drift time, CCS and intensity.
- 4D peak picking: Feature detection using m/z, retention time, drift time and intensity.
- CCS library: Database of experimentally measured collision cross sections.
- Vendor-neutral: Compatible with data from multiple instrument vendors.
- Mass defect filtering: Filtering compounds by characteristic mass defect ranges.
- Homologous series detection: Finding compounds differing by repeating units.
- Extracted Ion Chromatogram (EIC): Chromatogram for one selected m/z.
- Negative electrospray ionization (ESI−): Negative ion acquisition mode.
- QTOF: Quadrupole Time-of-Flight mass spectrometer.
- DDA (Data-Dependent Acquisition): MS/MS acquired for selected precursor ions.
- All Ions acquisition: DIA-style acquisition fragmenting everything simultaneously.
- PNNL Preprocessor: Software that converts Agilent All Ions data into pseudo-DDA spectra.
- Confidence scoring: FluoroMatch's A–E scoring system for PFAS annotation confidence.
About
Rather than relying solely on MS/MS fragmentation, the software combines multiple independent pieces of evidence including:
- Accurate mass
- Collision Cross Section (CCS)
- Homologous series
- Mass defect
- Formula prediction
- Drift time
- Retention time
Software: https://github.com/Innovative-Omics/FluoroMatch
Interactive visualization: https://innovativeomics.com/datasets
Dataset
MassIVE - ftp://massive.ucsd.edu/v07/MSV000096605/
Relevant for fluorine detection
Fluorinated molecules occupy a unique CCS region
- lower CCS than non-fluorinated molecules
- for the same m/z
Multiple weak signals outperform one strong signal
Instead of relying only on MS/MS:
- exact mass
- CCS
- homologous series
- mass defect
- retention time
- drift time